/*
 * Copyright (C) 2011 The Android Open Source Project Copyright (C) 2011 Jake Wharton
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */
package com.viewpagerindicator;

import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
import static android.view.ViewGroup.LayoutParams.WRAP_CONTENT;
import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.HorizontalScrollView;
import android.widget.LinearLayout;
import android.widget.TextView;

import com.jeremyfeinstein.slidingmenu.lib.R;

/** This widget implements the dynamic action bar tab behavior that can change across different
 * configurations or circumstances. */
public class TabPageIndicator extends HorizontalScrollView implements PageIndicator {
    /** Title text used when no title is provided by the adapter. */
    private static final CharSequence EMPTY_TITLE = "";

    /** Interface for a callback when the selected tab has been reselected. */
    public interface OnTabReselectedListener {
        /** Callback when the selected tab has been reselected.
         * 
         * @param position Position of the current center item. */
        void onTabReselected(int position);
    }

    private Runnable mTabSelector;

    // private final OnClickListener mTabClickListener = new OnClickListener() {
    // @Override
    // public void onClick(View view) {
    // CustomTabView tabView = (CustomTabView) view;
    // final int oldSelected = mViewPager.getCurrentItem();
    // final int newSelected = tabView.getIndex();
    // mViewPager.setCurrentItem(newSelected);
    // if (oldSelected == newSelected && mTabReselectedListener != null) {
    // mTabReselectedListener.onTabReselected(newSelected);
    // }
    // }
    // };

    class TabClickListener implements OnClickListener {
        int index;

        public TabClickListener(int index) {
            super();
            this.index = index;
        }

        @Override
        public void onClick(View v) {
            final int oldSelected = mViewPager.getCurrentItem();
            final int newSelected = index;
            mViewPager.setCurrentItem(newSelected);
            if (oldSelected == newSelected && mTabReselectedListener != null) {
                mTabReselectedListener.onTabReselected(newSelected);
            }
        }

    }

    private final IcsLinearLayout mTabLayout;

    private ViewPager mViewPager;
    private ViewPager.OnPageChangeListener mListener;

    private int mMaxTabWidth;
    private int mSelectedTabIndex;

    private OnTabReselectedListener mTabReselectedListener;

    public TabPageIndicator(Context context) {
        this(context, null);
    }

    public TabPageIndicator(Context context, AttributeSet attrs) {
        super(context, attrs);
        setHorizontalScrollBarEnabled(false);

        mTabLayout = new IcsLinearLayout(context, R.attr.vpiTabPageIndicatorStyle);
        mTabLayout.setGravity(Gravity.CENTER);
        addView(mTabLayout, new ViewGroup.LayoutParams(WRAP_CONTENT, MATCH_PARENT));
    }

    public void setOnTabReselectedListener(OnTabReselectedListener listener) {
        mTabReselectedListener = listener;
    }

    @Override
    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
        final boolean lockedExpanded = widthMode == MeasureSpec.EXACTLY;
        setFillViewport(lockedExpanded);

        final int childCount = mTabLayout.getChildCount();
        if (childCount > 1
                && (widthMode == MeasureSpec.EXACTLY || widthMode == MeasureSpec.AT_MOST)) {
            if (childCount > 2) {
                mMaxTabWidth = (int) (MeasureSpec.getSize(widthMeasureSpec) * 0.4f);
            } else {
                mMaxTabWidth = MeasureSpec.getSize(widthMeasureSpec) / 2;
            }
        } else {
            mMaxTabWidth = -1;
        }

        final int oldWidth = getMeasuredWidth();
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        final int newWidth = getMeasuredWidth();

        if (lockedExpanded && oldWidth != newWidth) {
            // Recenter the tab display if we're at a new (scrollable) size.
            setCurrentItem(mSelectedTabIndex);
        }
    }

    private void animateToTab(final int position) {
        final View tabView = mTabLayout.getChildAt(position);
        if (mTabSelector != null) {
            removeCallbacks(mTabSelector);
        }
        mTabSelector = new Runnable() {
            @Override
            public void run() {
                final int scrollPos = tabView.getLeft() - (getWidth() - tabView.getWidth()) / 2;
                smoothScrollTo(scrollPos, 0);
                mTabSelector = null;
            }
        };
        post(mTabSelector);
    }

    @Override
    public void onAttachedToWindow() {
        super.onAttachedToWindow();
        if (mTabSelector != null) {
            // Re-post the selector we saved
            post(mTabSelector);
        }
    }

    @Override
    public void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        if (mTabSelector != null) {
            removeCallbacks(mTabSelector);
        }
    }

    // private void addTab(int index, CharSequence text, int iconResId) {
    // final TabView tabView = new TabView(getContext());
    // tabView.mIndex = index;
    // tabView.setFocusable(true);
    // tabView.setOnClickListener(mTabClickListener);
    // tabView.setText(text);
    //
    // if (iconResId != 0) {
    // tabView.setCompoundDrawablesWithIntrinsicBounds(iconResId, 0, 0, 0);
    // }
    //
    // mTabLayout.addView(tabView, new LinearLayout.LayoutParams(0, MATCH_PARENT, 1));
    // }

    /** 添加自定义的Tab View
     * 
     * @param index
     * @param text
     * @param iconResId */
    private void addCustomTab(int index, CharSequence text, int iconResId) {
        View view = View.inflate(getContext(), R.layout.item_viewpager_tab, null);
        View selector = view.findViewById(R.id.selector);
        TextView tabView = (TextView) view.findViewById(R.id.title);
        if (index == 0) {
            tabView.setGravity(Gravity.RIGHT);
        }
        view.setOnClickListener(new TabClickListener(index));
        tabView.setText(text);

        // if (iconResId != 0) {
        // tabView.setCompoundDrawablesWithIntrinsicBounds(0, 0, 0,
        // R.drawable.custom_tab_indicator_selected_pressed);
        // }

        mTabLayout.addView(view, new LinearLayout.LayoutParams(0, MATCH_PARENT, 1));
    }

    @Override
    public void onPageScrollStateChanged(int arg0) {
        if (mListener != null) {
            mListener.onPageScrollStateChanged(arg0);
        }
    }

    @Override
    public void onPageScrolled(int arg0, float arg1, int arg2) {
        if (mListener != null) {
            mListener.onPageScrolled(arg0, arg1, arg2);
        }
    }

    @Override
    public void onPageSelected(int arg0) {
        setCurrentItem(arg0);
        if (mListener != null) {
            mListener.onPageSelected(arg0);
        }
    }

    @Override
    public void setViewPager(ViewPager view) {
        if (mViewPager == view) {
            return;
        }
        if (mViewPager != null) {
            mViewPager.setOnPageChangeListener(null);
        }
        final PagerAdapter adapter = view.getAdapter();
        if (adapter == null) {
            throw new IllegalStateException("ViewPager does not have adapter instance.");
        }
        mViewPager = view;
        view.setOnPageChangeListener(this);
        notifyDataSetChanged();
    }

    @Override
    public void notifyDataSetChanged() {
        mTabLayout.removeAllViews();
        PagerAdapter adapter = mViewPager.getAdapter();
        IconPagerAdapter iconAdapter = null;
        if (adapter instanceof IconPagerAdapter) {
            iconAdapter = (IconPagerAdapter) adapter;
        }
        final int count = adapter.getCount();
        for (int i = 0; i < count; i++) {
            CharSequence title = adapter.getPageTitle(i);
            if (title == null) {
                title = EMPTY_TITLE;
            }
            int iconResId = 0;
            if (iconAdapter != null) {
                iconResId = iconAdapter.getIconResId(i);
            }
            addCustomTab(i, title, iconResId);
        }
        if (mSelectedTabIndex > count) {
            mSelectedTabIndex = count - 1;
        }
        setCurrentItem(mSelectedTabIndex);
        requestLayout();
    }

    @Override
    public void setViewPager(ViewPager view, int initialPosition) {
        setViewPager(view);
        setCurrentItem(initialPosition);
    }

    @Override
    public void setCurrentItem(int item) {
        if (mViewPager == null) {
            throw new IllegalStateException("ViewPager has not been bound.");
        }
        mSelectedTabIndex = item;
        mViewPager.setCurrentItem(item);

        final int tabCount = mTabLayout.getChildCount();
        for (int i = 0; i < tabCount; i++) {
            final View child = mTabLayout.getChildAt(i);
            final boolean isSelected = (i == item);
            child.setSelected(isSelected);
            if (isSelected) {
                animateToTab(item);
            }
        }
    }

    @Override
    public void setOnPageChangeListener(OnPageChangeListener listener) {
        mListener = listener;
    }

    // private class TabView extends TextView {
    // private int mIndex;
    //
    // public TabView(Context context) {
    // super(context, null, R.attr.vpiTabPageIndicatorStyle);
    // }
    //
    // @Override
    // public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    // super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    //
    // // Re-measure if we went beyond our maximum size.
    // if (mMaxTabWidth > 0 && getMeasuredWidth() > mMaxTabWidth) {
    // super.onMeasure(MeasureSpec.makeMeasureSpec(mMaxTabWidth, MeasureSpec.EXACTLY),
    // heightMeasureSpec);
    // }
    // }
    //
    // public int getIndex() {
    // return mIndex;
    // }
    // }

    private class CustomTabView extends View {
        public CustomTabView(Context context) {
            super(context);
        }

        private int mIndex;


        public int getIndex() {
            return mIndex;
        }
    }
}
